Articles in 2021

Lithium-ion batteries suffer from declining performance when the electrolyte decomposes. Now, low-dosage cryogenic transmission electron microscopy (cryo-TEM) visualizes how the common solid electrolyte interface component lithium carbonate decomposes and how additives stabilize the interface.

CO₂ is prominent in the Earth’s and exoplanetary atmospheres, but its excited state photochemistry is not yet fully understood. Here the authors identify gradual quenching of the diffuse vibrational structure in supercritical CO₂ electronic spectra under pressures up to 137 bar.

Halogen–sodium exchange reactions with neopentyl sodium provides access to a range of aryl and alkenyl organosodium compounds in situ, as an alternative to organolithium reagents.

Porous carbon materials are used widely in catalysis, electrochemistry, or as sorbents, but pore size control continues to be a challenge in their syntheses. Here the authors show that the 3D molecular structure of the carbon sources allows to control the pore size of the resulting carbon materials at the Ångstrom-level.

Fullerenes are intrinsically electron deficient species which can facilitate challenging transformations in organic chemistry. Here fullerene-fused alkoxy ethers are shown to undergo copper-promoted oxidation by single electron transfer to the corresponding ketones via a fullerene radical cation intermediate.

Sudden ionisation of larger molecules can initiate a correlation-driven process called charge migration, but due to its short time scale this process is challenging to observe. Here, the authors ionise adenine with extreme ultraviolet light and observe electron correlation in the molecule at the attosecond scale in real-time.

Proline plays an important role in determining the structures of proteins and peptides, but the conformer landscape of proline is still not fully mapped. Here, the authors show the conformer-specific cation fragmentation and photoelectron circular dichroism of proline during its vacuum ultraviolet photoionization.

Permanent magnets constructed from metal ions and organic linkers using molecular design principles could bring transformative advances in areas such as energy conversion, transportation, and information storage. This comment highlights the recent discovery of a metal–organic magnet ordering at 242 °C, and discusses future research directions and possible applications involving such materials.

Air-sensitive molybdenum olefin metathesis catalysts are known to form stable but inactive adducts with appropriate chelating ligands, but regenerating the active catalyst requires the use of Lewis acids and vigorous conditions. Here, tuning the electron donor capacity of the ligands leads to air-stable solid adducts of tungsten and molybdenum alkylidenes that spontaneously release the active catalysts in solution.

Upconverting anthropogenic CO₂ into valuable chemicals generally involves separation and concentration steps of the feed gas. Here, the authors report an efficient, one-pot method for synthesizing urea derivatives from alkyl ammonium carbamates obtained from atmospheric CO₂ or simulated exhaust gas with low concentrations of CO₂.

Glycosaminoglycans are an important class of carbohydrates, but pose substantial analytical challenges. Here ToF-SIMS combined with multivariate analysis distinguishes six classes of glycosaminoglycans, including distinguishing heparin samples from different animal sources at a sensitivity as low as 0.001 wt%

Atomically precise gold nanoclusters hold promise as non-linear optical probes for biological imaging. Here functionalized luminescent gold nanoclusters bind free carbonyls via oxime bond formation, allowing detection of carbonylated proteins via gel electrophoresis and fluorescence imaging.

Photoactive ruthenium metal complexes are relevant luminescent DNA markers, but deciphering their local excited state dynamics in complex biochemical environments is challenging. Here the authors combine femtosecond and nanosecond pump-probe spectroscopy to elucidate the local hydration effects and ³MLCT relaxation dynamics of [Ru(phen)₂(dppz)]²⁺ in two G-quadruplexes.

Uranium silicide is proposed as a highly accident tolerant light water reactor nuclear fuel, but its behavior under high-temperature, aqueous conditions is poorly studied. Here, uranium silicide is shown to decompose and fully oxidize when the passive uranium silicate layer is destabilized under hydrothermal conditions over 300 °C.

Hydrosilylation of allyl chloride with trichlorosilane is industrially important but often proceeds unselectively. Here a Rh(I) catalyst which achieves 99% selectivity on gram scale is described, based on bidentate phosphine ligands.

Molecular dynamics-based approaches to calculate absolute protein–ligand binding free energy often rely on equilibrium free energy perturbation (FEP) protocols. Here, the authors study ligands binding to bromodomains and T4 lysozyme and find that both equilibrium and non-equilibrium approaches converge to the same results with the non-equilibrium method converging faster than FEP.

Palladium can absorb high volumes of hydrogen, but the morphology and 3D displacements occurring during palladium hydride phase formation are not fully characterized in the literature. Here, the authors use Bragg coherent diffraction imaging to map the strain within an individual palladium nanoparticle before and during hydride phase transformation, identifying a characteristic displacement caused by the seed particle in the nanocrystal.

How the structure of fibril-forming peptides influences the material and structural characteristics of their resultant assemblies remains an open question. Here, aliphatic to aromatic amino acid substitution in such peptides is shown to have little effect on the tendency to form amyloid-like fibrils, but instead alters the pathway by which they form and the mechanical properties of peptide supramolecular assemblies.

Preparation of cyclobutanes with four different substituents is rare and often arduous. Here a cocrystallisation strategy enables the intermolecular [2+2] cross-photoreaction of non-symmetrical stilbene derivatives to obtain chiral tetrasubstituted cyclobutanes with up to four different substituents in quantitative yield.

Controlling the helical structure of peptide foldamers requires detailed understanding of the relationship between primary and secondary structure. Here the effect of monomer stoichiometry and configuration on the helical structures of peptide nucleic acids bearing sulfono pendants is examined.